Controlling device for electric motors for driving sewing-machines, small lathes, &amp;c.



1m 850,947. PATENTED APR. 23, 1907. r H. MIDGLEY & B. REED.

CONTROLLING DEVICE FOR ELECTRIC MOTORS FOR DRIVING SEWING MAGHINES, SMALL LATHES, 8m.

APPLIOATI ON FILED JAN.31.1906.

kamas. ,ZWWZ/WZY ALBERT-HENRY Mme-Liar AND BENJAAHN TEES, LONDON, ENGLAND.

C(lNTROLLlNG DEVICE FOR ELEClRit Mtl'lllili FUR DiilVll lG SEWlNG-iii/iCl-HNES, SMALL LATHES, dc.

i pecification of Letters Eatented to,

Application filed January 31,190ii. Serial No. 298,827.

To all whom it may concern: I

Be it known that We, ALBERT HENRY MIDGLEY- and BENJAMIN REED, sub ects or the Kin of Great Britain and lreland end- This invention relates to a controlling device for direct-current electric motors, and consists, essentially, in a new or improved controlling switch bymeans of which it is ossible to at once run the requisite machine at fiullspeed, slow speed, varying speed, or stopped alto ether by the release or other.- wise of a sing clever, such controlling device being especially intended for sewing-machines electrically operated, but applicable also to other machines, such as.small lathes and the like.

Referring to the accompanying sheet of explanatory drawings in carrying the said invention into efiect, a represents a case or be); of any suitable size and construction, and b the switchboard carried therein. 0n pivot c is mounted the (preferably spring controlled) lever d, adapted to enga e at it outer end with a sector 6 and with tie stops or contacts f of the resistance 9, arranged in any suitable manner within the case or box. This resistance 9 is connected, as snown, with the terminal h, and pivot c of the lever 02 with the terminal 'L. The sector 6 is connected to terminal 7', and terminal j to the terminal it, and terminal Z to terminal 'm to terminal n, which represents one end of the field-winding oi the motor, the other end 0 of the winding being connected to the terminal 71., terminals 79 and g of the commutator-brushes being connected to terminals 7c and i.

In connecting. up the controlling-switch (indicated by A) as a Whole with the motor B and supply mains the terminals m, h, t, and 7c on the controlling-switch are connected up to the terminals n, 0, p, and (1, respectively, on the motor, and the terminals and Z to the mains 1' and s.

By the use of a controlling device con- I structed in accordance with this invention it is possible tostart the motor, and consequently the machine, regulate the machine according to the amount of resistance put in, or to stop the same instantaneously. For instance, when the contact-lever d is in the position shown in the accompanying drawingsi. e., in engagement wi, J. the sector the mote is at rest; but ii a d lever be moved in the direction of the arrow the motor will start the instant said lever 01 has left the sector 6 an stops or contacts f connected to the re the motor increasing as they contact-lever traverses over the stops j" of said resistance. now the lever at he moved in direction opposite the arrow, the speed decreases rntil said lever makes contact with the sector 6 when the supply of current is cut oil direc tly the lever has passed over the stops f. in order to obtain instantaneous stop, the lever must make contact both with the sector e and one of the tines contacts f op esite said sector. it will be observed that this action is secured by reason of the fact that when the lever 61 contacts with both the sector c and with one of the contacts f the motor-armature is short-circuite'd while the fields are lrept excited, thereby providing a the armature-shaft and stops the machinery driven thereby. The controlling device is made of such a shape and size as to be fitted in any convenient place for instance, be neath the table a sewing-inachine-in which case the lever d is provided with a spring-controlled drum '6 and is operated by a cord u or the like ccnnected'to any suitable arrangement of pedal, or the lever d may be operated by a handle or in any suitable manner without departing -from the nature of the invention.

l i licit we claim as new, and desire to secure by Letters Patent of the "United States, is V in a controlling device for'electric motors, the combination with the motor, of a switch hoard having a plurality of resistance-consistance having connections with the individual resistance-contacts, a group-of euro iliary contacts arranged on the arc of a circle beyond and connected with one of the terminals of said resistance-contacts, a fieldwire connection from the 1notor-field to the resistance contacts, a sector contact included in the supply-circuit and having a connection with the motor-armature, said 1 sector-contact being arranged concentric tance g, the speed 02;

dynamic brake which immediately arrests tacts arranged on the arc of a circle, a re-- its ' to but spaced from said auxiliary contacts,

In testimony'whereof we have affixed ou r signatures in presence of two witnesses.

ALBERT HENRY MIDGLEY, BENJAMIN and e suitably-operated contact-lever arranged to engage the sector-contact, and also said other contacts, the said contactlever being adapted to simultaneously en- Witnesses: gage the sector-contact and 1-11 auxiliary H. D. JURNESER. contact. A; NULTEY. 

